Yes, many types of peel-and-stick wallpaper can be used in bathrooms, especially those made of vinyl or polyester. However, its success depends heavily on the level of moisture and ventilation. In bathrooms with good ventilation, such as those with fans, it can be a durable option. Peel-and-stick wallpaper may not adhere as well as traditional wallpaper in very humid conditions. For bathrooms that see a lot of moisture, like a kids' bathroom or a full bath with a steamy shower and poor ventilation, even high-quality peel-and-stick wallpaper is likely to peel over time.

It’s possible to hang your own wallpaper, but the process is tedious and potentially frustrating, and it can be challenging to get seams to line up and look clean and professional. Plus, depending on the type of wallpaper you’re installing, using too much or too little adhesive could cause damage to your drywall or plaster, peeling, and bubbling in the final product. It’s usually a better idea to hire a professional wallpaper installer to do the work for you, as the relatively low cost is justifiable, if only to avoid damage to your walls.

Ideally, you want to ask the wallpaper installers you’re considering for examples of past work, and references you can call. These will prove that the installer can handle your job, make your room look professional, and will also give you some insight into the kind of customer service you can expect. Before you start calling companies, you might want to narrow down your options by finding installers with mostly positive reviews online.

When choosing materials for finishing basement walls, consider factors such as moisture resistance, durability, and fire resistance. Opt for materials specifically designed for basement environments, like moisture-resistant drywall or cement board. Insulation with vapor barriers can help regulate temperature and prevent condensation. Consider using mold-resistant paints or coatings. 

Research and consult with experts to select materials that are suitable for your specific basement conditions and intended use. Prioritize quality and compatibility to achieve long-lasting and aesthetically pleasing results.